In the case of bipolar, symptoms can be misconstrued as signs of chronic depression, anxiety, or even just moodiness. "Chalking it up to moodiness or trouble at work or tiredness is pretty common," Carrie Bearden, PhD, an assistant professor in the department of Psychiatry and Biobehavioral Sciences at UCLA told Health in a previous interview. "The disorder varies in severity."

However, there are some red flags that you or a loved one are experiencing more than just mood swings or tiredness: Are your moods very extreme, and generally pivot between high and low? For example, do you experience extreme exuberance along with episodes of depression? During these depressive states, do you experience significant trouble with your appetite, energy, and sleep? Do you find it’s challenging to complete tasks, and have a slew of half-complete projects in your life?

These are just a few potential symptoms of the serious mental illness. Watch this video to learn more about the subtle signs of bipolar 1 disorder.